1. Field of the Invention
The present invention relates service provisioning by means of a communication system, and more particularly to provisioning of services in arrangements wherein the user needs to subscribe to services.
2. Description of the Related Art
A communication system is a facility that enables communication between two or more entities such as user terminal equipment and/or networks entities and other nodes associated with the communication system. The communication may comprise, for example, communication of voice, electronic mail (email), text messages, data, multimedia and so on.
The communication may be provided via fixed line and/or wireless communication interfaces. A feature of the wireless communication systems is that they provide mobility for the users thereof. An example of communication systems providing wireless communication is a public land mobile network (PLMN). An example of the fixed line systems is a public switched telephone network (PSTN).
A communication system typically operates in accordance with a given standard or specification which sets out what the various elements of the system are permitted to do and how that should be achieved. For example, the standard or specification may define if the user, or more precisely, user equipment is provided with a circuit switched service or a packet switched service or both. Communication protocols and/or parameters which shall be used for the connection are also typically defined. For example, the manner how communication shall be implemented between the user equipment and the elements of the communication network is typically based on a predefined communication protocol. In other words, a specific set of “rules” on which the communication can be based on needs to be defined to enable the user equipment to communicate via the communication system.
Each communication system operates by running various different functions. The functions of various communication systems have been developed quite independently from each other. Thus it is possible that two communication systems such as two different communication networks handle a function in a different manner. For example, different and non-compatible protocols may be used for service provisioning in different communication systems.
For example, in communication environments such as those based on protocols such as the Internet Protocol (IP) or the Session Initiation Protocol (SIP) or the current third generation (3G) communication network architectures it is assumed that various servers are used for handling the provisioning of different communication services for users. In such communication systems the communication connections may not be based on a “circuit” between the communicating nodes, but the messages may rather be transported as packets that are provided with destination address information. Hence the name packet switched systems. The server entities and the user equipment may communicate with each other based on appropriate protocols providing such a connectionless operation.
From the above the Session Initiation Protocol (SIP) is an application-layer control protocol for creating, modifying and terminating sessions with one or more participants. A user connected to a SIP based communication system may communicate with various entities of the communication system based on standardised SIP messages. Examples of the possible sessions include Internet multimedia conferences, Internet telephone calls, and multimedia distribution. Those interested will find a more detailed description of the SIP from an Internet Engineering Task Force (IETF) protocol specification by J. Rosenberg et al titled “SIP: Session Initiation Protocol”, RFC 3261, July 2002. This document is incorporated herein by reference.
An Internet Engineering Task Force (IETF) protocol specification by A. Roach titled “SIP—Specific Event Notification”, RFC 3265, July 2002 describes a SIP event framework providing means to establish an IP-based event delivery mechanism. This document is also incorporated herein by reference.
Many scenarios are likely to be realized based on the SIP event notification framework. For instance, presence subscriptions and notifications allow for subscribing to a presence service wherein the subscriber is notified about changes in the presence status of e.g., a friend or other target user. Other scenarios include registrations for services and content available via the IP based Internet, changes in access rights for certain resources and so on. It is also possible to offer services such as reports regarding changes in the home through SIP event messaging services wherein homeowners can be notified through SIP event notifications upon predefined changes in the status of their homes.
The SIP event framework does not have any provisions for non-SIP-enabled user equipment. Thus the SIP event framework assumes that the services are always used by means of IP-enabled user equipment and even more importantly a SIP-enabled user equipment. However, the current mobile user equipment such as second generation mobile phones does not provide capabilities for SIP. Thus a large number of mobile user equipment could not be able to use services that are offered based on the SIP.
There have been proposals for delivering SIP notifications to user equipment by means of messages that are based on some other protocols. For example, Short Message Service (SMS) of the second generation the GSM mobile phone system can be used to transfer text messages to mobile phones today, and is widely used and supported in the GSM networks.
Products have already been offered for enabling use of the SIP based services by means of user equipment that is not SIP enabled. For example, Hotsip AB, Sweden, offers a presence and messaging gateway that offers a notification engine which includes a gateway from the SIP communication environment to the SMS environment. The arrangement proposed by Hotsip AB is disclosed in more detail in international patent application publication No. WO 02/05534. Dynamicsoft, Inc, USA, offers another gateway that is capable of translation wireless application protocol (WAP) and SMS content into SIP based messages that can then be delivered to an SIP-enabled device. The SIP enabled device can be a mobile or a fixed device.
However, these solutions are fixed to the particular SIP applications and in reality work only one-way. That is, the proposed gateways are merely for delivering notifications from e.g., a SIP presence server to the GSM user equipment by means of predefined standard messages. Furthermore, because the messages can only be selected among a list of predefined messages, the notifications are application specific, i.e., specific for particular SIP services such as presence service. The proposed gateways are based on closed concept i.e. need to be run and managed by the operator of the user's telecommunication network. Therefore any external service providers are excluded from offering SIP based services for non SIP enabled users. There is no teaching in the prior art how the gateway arrangement could be used for a variety of SIP services. Furthermore, the proposed gateways do not allow the user to subscribe to any of the SIP services. Instead, the subscriptions to the given services are not based on the SIP event framework but use the existing GSM framework, e.g., a call to a specific telephone number.
Thus, there is a need for a more flexible solution for enabling subscription and use of services provided by a service provided entity connected to a network operating accordance with a communication protocol by means of a user equipment that is not adapted for communication in accordance with the communication protocol.